SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea98a3655c277f0491913bf66370832fbc73fd0ebd468d636cb9a259a6f70140' 
  AND token = 'mDMyHr6zX2qGtnWvu1qgEOtfYR6IIjoZUVDP6pAd8Mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}